aspiration vs raison d'être

aspiration

noun
  • The act of aspiring or ardently desiring; an ardent wish or desire, chiefly after what is elevated or spiritual (with common adjunct adpositions being to and of). 

  • The action of aspirating. 

  • A burst of air that follows the release of some consonants. 

raison d'être

noun
  • Reason for being. The claimed reason for the existence of something or someone; the sole or ultimate purpose of something or someone. 

How often have the words aspiration and raison d'être occurred in a corpus of books? (source: Google Ngram Viewer )